<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      #box {
        width: 200px;
        height: 200px;
        background-color: red;
      }
    </style>
  </head>
  <body>
    <div id="box"></div>
    <script>
      function enableLongTap(ele) {
        let event = new CustomEvent("长按");
        let timer = 0;
        let isLongTap = false;
        ele.addEventListener("mousedown", () => {
          isLongTap = true;
          clearTimeout(timer);
          timer = setTimeout(() => {
            ele.dispatchEvent(event);
          }, 500);
          let move = () => {
            clearTimeout(timer);
          };
          let end = () => {
            clearTimeout(timer);
            document.removeEventListener("mouseover", move);
            document.removeEventListener("mousemove", move);
          };
          document.addEventListener("mouseover", move);
          document.addEventListener("mousemove", move);
        });
      }
      let box = document.querySelector("#box");
      enableLongTap(box);
      box.addEventListener("长按", ()=>{
        console.log("这是个长按事件");
      })
    </script>
  </body>
</html>
